Why would they want one? Simple really much the same as the nuclear powers even us. Interfere with us too much and we will use them. Various rules in different countries but all boil down to that.If the Iranians wanted a nuclear bomb they would probably have one by now.
That just leaves pre-emptive strikes. Simple detect the launch and send your own immediately plus submarines.
Reminds me of a long walk along a beach in Norfolk and feeling a bit odd in a deserted section of it. Further on the radar units, lots of them could be seen even where we had been walking but needed to jump up to see those. Doubt if they were early warning but...........
